Sign up to receive free email alerts when patent applications with chosen keywords are publishedSIGN UP

Abstract:

The subject matter of the present Application is two-component
compositions whose first component is a mixture of reactive epoxy resins
and optionally further formulation constituents which contains, based on
the mass of all epoxy resins, a) at least 10 wt % of an epoxy
group-containing reaction product of epichlorohydrin with polypropylene
glycol which has an epoxy equivalent weight of at least 250 g/eq, and b)
at least 10 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq, and whose second component contains at least one
thiol group-containing hardener for epoxy resins.

Claims:

1. A two-component composition whose first component is a mixture of
reactive epoxy resins and optionally further formulation constituents
which contains, based on the mass of all epoxy resins, a) at least 10 wt
% of an epoxy group-containing reaction product of epichlorohydrin with
polypropylene glycol which has an epoxy equivalent weight of at least 250
g/eq, and b) at least 10 wt % of an epoxy group-containing reaction
product of epichlorohydrin with a novolac resin which has an epoxy
equivalent weight of at least 175 g/eq, and whose second component
contains at least one thiol group-containing hardener for epoxy resins.

2. The composition according to claim 1, wherein the first component
further contains at least 10 wt % of an epoxy group-containing reaction
product of epichlorohydrin with bisphenol A which has an epoxy equivalent
weight of at least 500 g/eq.

3. The composition according to claim 1, wherein the second component
additionally contains an amine group-containing hardener for epoxy
resins.

4. The composition according to claim 1, wherein component a) has an
epoxy equivalent weight of at least 300 g/eq, and/or component b) has an
epoxy equivalent weight of at least 190 g/eq.

5. The composition according to claim 1, wherein component b) contains or
represents a novolac resin having an epoxy functionality of at least 3.

7. The composition according to claim 1, wherein it contains, based on
the mass of all epoxy resins, the following components: a. 10 to 60 wt %
of an epoxy group-containing reaction product of epichlorohydrin with
polypropylene glycol which has an epoxy equivalent weight of at least 250
g/eq, b. 15 to 85 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq, and c. 0 to 70 wt % of an epoxy group-containing
reaction product of epichlorohydrin with at least one bisphenol which has
an epoxy equivalent weight of at least 500 g/eq.

8. The composition according to claim 1, wherein its second component
contains or represents a hardener for epoxy resins that is effective in a
temperature range from 0 to 60.degree. C., in particular from 0 to
25.degree. C.

9. The composition according to claim 1, wherein the first component
contains, in addition to the mixture of epoxy resins, at least one
inorganic and/or organic filler.

10. A dispensing system that comprises two separate containers which,
separately from one another, contain the first and the second component
of the compositions according to claim 1, as well as a dispensing
apparatus.

Description:

[0001] The present invention relates to a two-component adhesive based on
a specific epoxy resin system. The epoxy resin system according to the
present invention makes it possible to provide, without the use of
components that are categorized as toxic, irritating, or sensitizing and
that would require corresponding labeling under European law, adhesives
that are equivalent in quality to conventional adhesives in terms of
utilization properties.

[0002] Epoxy-based resin systems have been successfully used for some time
as adhesives or repair compounds for consumers, hobbyists, and craftsmen,
and in the aviation, automotive, or electrical industry, as adhesives or
sealants or for the coating of surfaces, or as resin systems with a
number of different materials for the manufacture of composite materials.
Hardenable formulations that contain epoxy/hardener mixtures are suitable
in particular as structural adhesives. One important property of the
unhardened resin system is its viscosity, which is significant in terms
of handling and processability. Important material properties of the
hardened formulations are, among others, adhesive power (often determined
as tensile shear strength) and modulus of elasticity.

[0003] Reactive epoxy resin systems of the existing art often contain
constituents that have been categorized as toxic, irritating,
sensitizing, and/or hazardous to water resources, and can result, for
example, in contact dermatitis during processing. According to European
law, such preparations must be provided with the corresponding hazard
label (e.g. C, Xn, Xi, N). For reasons of environmental protection,
safety, and industrial hygiene, there is a desire for reactive epoxy
resin-containing preparations that do not require labeling under European
law and that exhibit a reduced sensitizing potential, but that meet
technical requirements with regard to processability and adhesive
properties.

[0004] It is known that reactive epoxy resins having a molar weight above
700 g/mol are not sensitizing and are not subject to labeling
requirements. Examples thereof are high-molecular-weight solids based on
DGEBA (diglycidyl ethers of bisphenol A), and liquid epoxy-terminated
polyethers with a high epoxy equivalent weight. These do not, however
exhibit the viscosity properties necessary for processing prior to
curing, and/or the necessary strength properties after curing.
High-molecular-weight solid epoxy novolacs have the high epoxy
functionality necessary for high strength (and, correspondingly, a low
epoxy equivalent weight), but are not processable because of their high
viscosity at room temperature.

[0005] An object of the present invention was therefore to develop a
hardenable epoxy resin that is advantageous in toxicological and
dermatological terms and nevertheless has no disadvantages in the context
of utilization properties, in particular viscosity during processing
and/or strength after curing.

[0006] It has now been found, surprisingly, that suitable mixtures of
different reactive epoxy resins result in the desired property
combination of freedom from labeling requirements, processability, and
adhesive properties.

[0007] A first subject of the present invention is therefore a
two-component composition whose first component is a mixture of reactive
epoxy resins and optionally further formulation constituents which
contains, based on the mass of all epoxy resins,

[0008] a) at least 10 wt % of an epoxy group-containing reaction product
of epichlorohydrin with polypropylene glycol which has an epoxy
equivalent weight of at least 250 g/eq, and

[0009] b) at least 10 wt % of an epoxy group-containing reaction product
of epichlorohydrin with a novolac resin which has an epoxy equivalent
weight of at least 175 g/eq, and

whose second component contains at least one thiol group-containing
hardener for epoxy resins.

[0010] According to the present invention, a "reactive epoxy resin" is
understood as a prepolymer that has an average epoxy functionality
greater than 1. Because of the reactive epoxy groups, the prepolymer can
be reacted with further molecules (called "hardeners") that are reactive
with respect to epoxy groups, and thereby be "cured" or "hardened."

[0011] The composition according to the present invention contains, as a
first component a) essential to the invention, at least 10 wt % of an
epoxy group-containing reaction product of epichlorohydrin with
polypropylene glycol which has an epoxy equivalent weight of at least 250
g/eq.

[0012] In a preferred embodiment, the composition according to the present
invention contains 10 to 60 wt % of component a). A quantity range from
30 to 45 wt % is especially preferred. The quantity indications refer in
each case to the mixture of all epoxy resins, without the further
formulation constituents.

[0013] In the context of the work on which this invention is based, it was
possible to show that epoxy group-containing reaction products of
epichlorohydrin with polypropylene glycol having an epoxy equivalent
weight of at least 300 g/eq exhibit particularly advantageous properties.

[0014] Particularly preferred components a) are, according to the present
invention, the reactive epoxy resins marketed by the Dow company under
the commercial designations DER 732 (EEW 310 to 330 g/eq) and DER 732P
(EEW 310 to 330 g/eq).

[0015] It is particularly advantageous according to the present invention
if corresponding epoxy group-containing reaction products of
epichlorohydrin with polypropylene glycol having an epoxy equivalent
weight of less than 300 g/eq are contained in the compositions at a
proportion of at most 3 wt %, in particular at most 1 wt %, based in each
case on the first component made up of a mixture of reactive epoxy resins
and optionally further formulation constituents.

[0016] As a second component b) essential to the invention, the
composition according to the present invention contains at least 10 wt %
of an epoxy group-containing reaction product of epichlorohydrin with a
novolac resin which has an epoxy equivalent weight of at least 175 g/eq.

[0017] In a preferred embodiment, the composition according to the present
invention contains 10 to 85 wt % of component b). A quantity range from
30 to 45 wt % is especially preferred. The quantity indications refer in
each case to the mixture of all epoxy resins, without the further
formulation constituents.

[0018] In the context of the work on which this invention is based, it was
possible to show that epoxy group-containing reaction products of
epichlorohydrin with a novolac having an epoxy equivalent weight of at
least 180 g/eq, and in particular of at least 190 g/eq, exhibit
particularly advantageous properties.

[0019] Novolacs preferred according to the present invention are the
polycondensation products of formaldehyde with phenol and/or cresol.

[0020] It has furthermore proven to be advantageous if the reaction
products of epichlorohydrin and novolac have an epoxy functionality of at
least 3, in particular of at least 3.5.

[0021] Reaction products of epichlorohydrin and novolac which have an
epoxy equivalent weight of at least 175 g/eq and simultaneously an epoxy
functionality of at least 3 were found to be particularly convincing in
terms of the objects stated according to the present invention. Reaction
products of epichlorohydrin and novolac having an epoxy equivalent weight
of at least 180 g/eq and an epoxy functionality of at least 3, in
particular reaction products of epichlorohydrin and novolac having an
epoxy equivalent weight of at least 190 g/eq and an epoxy functionality
of at least 3.5, are particularly preferred.

[0022] The desired property combination of processability prior to curing,
and adhesion strength after curing, are most effectively achieved
thereby.

[0024] It is particularly advantageous according to the present invention
if corresponding reaction products of epichlorohydrin with novolac having
an epoxy equivalent weight of less than 175 g/eq are contained at a
proportion of at most 3 wt %, in particular at most 1 wt %, based in each
case on the first component made up of the mixture of reactive epoxy
resins and optionally further formulation constituents.

[0025] In order to ensure optimum processability of the compositions
according to the present invention, it has proven particularly
advantageous according to the present invention if the epoxy-containing
compositions have viscosities below 3000 Pas. Epoxy-containing
preparations having a viscosity below 500 PaS are very particularly
preferred. Viscosity measurements are accomplished according to the
present invention at 25° C. using a rheometer and the following
viscosity-dependent settings:

[0026] at a viscosity <0.25 Pa*s, measurement was performed using a
cone and plate (0.04°/25 mm) at a shear rate of 0 to 100/s;

[0027] viscosities >0.25 Pa*s and <10,000 Pa*s were measured using
parallel plates (25 mm/25 mm) at a shear rate of 0 to 100/s; and

[0028] viscosities >10,000 Pa*s were measured using parallel plates (25
mm/25 mm) and at an angular frequency of 100 rad/s.

[0029] According to the present invention, a measurement at a "shear rate
of 0 to 100/s" is understood as a measurement in which the shear speed is
increased, within 100 s, from 0/s to 100/s. The shear speed is then held
constant for 30 s, and then the result is determined.

[0030] A further essential property of the agents according to the present
invention is the so-called tensile shear strength. This is determined by
means of the following experimental setup:

[0031] Two sandblasted, cold-rolled steel specimens are wetted with the
adhesive to be tested, on an overlap area of 2.5 cm2 with a layer
thickness of 0.2 mm, and bonded. After corresponding curing, the tensile
shear strength of the adhesive is tested in accordance with DIN EN 1465
at a rate of 15 mm/min.

[0032] It has proven to be advantageous according to the present invention
if the adhesives exhibit, after they have cured, a tensile shear strength
above 8 MPa, in particular above 10 MPa. The speed of the curing process
plays no essential role in this context.

[0033] As a third component essential to the invention, the composition
according to the present invention contains at least one thiol
group-containing hardener for epoxy resins.

[0034] According to the present invention, a "thiol group-containing
hardener for epoxy resins" is understood as a compound that comprises at
least two thiol groups per molecule. It is particularly preferred
according to the present invention if the compound is one that is liquid
at 22° C.

[0035] According to the present invention it may be preferred, in a
specific embodiment, if the thiol group-containing hardener is a
polymeric compound.

[0071] It may be preferred according to the present invention if the
second component of the composition contains less than 25 wt %, in
particular less than 20 wt %, in particular less than 10 wt %, of one or
more of the following compounds, the quantity indications being based on
the entire composition of the second component: [0072] pentaerythritol
tetrakis(3-mercaptobutylate) (CAS 31775-89-0), [0073]
dipentenedimercaptan (CAS 4802-20-4), [0074] glycol dimercaptoacetate
(CAS 123-81-9), [0075] trimethylopropane tris-3-mercaptopropionate (CAS
33007-83-9), [0076] pentaerythritol tetra-3-mercaptopropionate (CAS
7575-23-7), [0077] DMDO (3,6-dioxa-1,8-octanedithiol), [0078]
1,2-ethanedithiol, [0079] 1,3-propanedithiol, [0080] 1,4-butanedithiol,
[0081] 1,3-butanedithiol, [0082] 2,3-butanedithiol, and [0083]
2,3-dimercapto-1-propanol.

[0084] The thiol group-containing hardeners are used by preference at a
ratio of 1 thiol equivalent hardener per 1 to 2 epoxy equivalent. This
means that the utilization mixture preferably comprises an excess of
reactive epoxy groups with respect to the reactive thiol groups.

[0085] In a preferred embodiment of the present invention, the first
component further contains at least 10 wt % of an epoxy group-containing
reaction product of epichlorohydrin with bisphenol A which has an epoxy
equivalent weight of at least 500 g/eq.

[0086] In this embodiment, compositions that contain, based on the mass of
all epoxy resins, the following components:

[0087] a) 10 to 60 wt % of an epoxy group-containing reaction product of
epichlorohydrin with polypropylene glycol which has an epoxy equivalent
weight of at least 250 g/eq,

[0088] b) 15 to 85 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq, and

[0089] c) 0 to 70 wt % of an epoxy group-containing reaction product of
epichlorohydrin with at least one bisphenol which has an epoxy equivalent
weight of at least 500 g/eq,

are accordingly particularly preferred.

[0090] Compositions that contain, based on the mass of all epoxy resins,
the following components:

[0091] a) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with polypropylene glycol which has an epoxy equivalent
weight of at least 250 g/eq,

[0092] b) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq, and

[0093] c) 10 to 40 wt % of an epoxy group-containing reaction product of
epichlorohydrin with at least one bisphenol which has an epoxy equivalent
weight of at least 500 g/eq,

are particularly preferred according to the present invention.

[0094] Compositions that contain, based on the mass of all epoxy resins,
the following components:

[0095] a) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with polypropylene glycol which has an epoxy equivalent
weight of at least 250 g/eq,

[0096] b) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq and an epoxy functionality of at least 3, and

[0097] c) 10 to 40 wt % of an epoxy group-containing reaction product of
epichlorohydrin with at least one bisphenol which has an epoxy equivalent
weight of at least 500 g/eq,

are furthermore particularly preferred according to the present
invention.

[0098] It has proven to be particularly advantageous according to the
present invention if the composition according to the present invention
contains 0 to 70 wt % of an epoxy group-containing reaction product of
epichlorohydrin with bisphenol A which has an epoxy equivalent weight of
at least 500 g/eq. A quantity range from 10 to 40 wt % is especially
preferred. The quantity indications refer in each case to the mixture of
all epoxy resins, without the further formulation constituents.

[0099] In the context of the work on which this invention is based, it was
possible to show that epoxy group-containing reaction products of
epichlorohydrin with bisphenol A having an epoxy equivalent weight of at
least 560 g/eq exhibit particularly advantageous properties.

[0112] It is particularly advantageous according to the present invention
if corresponding epoxy group-containing reaction products of
epichlorohydrin with bisphenol A which have an epoxy equivalent weight
below 500 g/eq are contained in the compositions at a proportion of at
most 3 wt %, in particular at a proportion of at most 1 wt %, based in
each case on the first component made up of a mixture of reactive epoxy
resins and optionally further formulation constituents.

[0113] Especially in toxicological terms, it has proven to be advantageous
if the compositions according to the present invention contain, in
addition to the aforesaid epoxy group-containing reaction products a),
b), and c) that are essential to the invention, less than 3 wt %, in
particular less than 1 wt %, of further epoxy group-containing reaction
products, based in each case on the first component made up of the
mixture of reactive epoxy resins and optionally further formulation
constituents.

[0114] In a particularly preferred embodiment of this subject, the mixture
of the epoxy resins is made up of

[0115] a) 10 to 60 wt % of an epoxy group-containing reaction product of
epichlorohydrin with polypropylene glycol which has an epoxy equivalent
weight of at least 250 g/eq,

[0116] b) 15 to 85 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq, and

[0117] c) 0 to 70 wt % of an epoxy group-containing reaction product of
epichlorohydrin with at least one bisphenol which has an epoxy equivalent
weight of at least 500 g/eq,

the quantities of constituents a), b), and c) adding up to 100 wt %.

[0118] In a very particularly preferred embodiment of this subject, the
mixture of the epoxy resins is made up of

[0119] a) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with polypropylene glycol which has an epoxy equivalent
weight of at least 250 g/eq,

[0120] b) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq, and

[0121] c) 10 to 40 wt % of an epoxy group-containing reaction product of
epichlorohydrin with at least one bisphenol which has an epoxy equivalent
weight of at least 500 g/eq,

the quantities of constituents a), b), and c) adding up to 100 wt %.

[0122] In a further very particularly preferred embodiment of this
subject, the mixture of the epoxy resins is made up of

[0123] a) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with polypropylene glycol which has an epoxy equivalent
weight of at least 250 g/eq,

[0124] b) 30 to 45 wt % of an epoxy group-containing reaction product of
epichlorohydrin with a novolac resin which has an epoxy equivalent weight
of at least 175 g/eq and an epoxy functionality of at least 3, and

[0125] c) 10 to 40 wt % of an epoxy group-containing reaction product of
epichlorohydrin with at least one bisphenol which has an epoxy equivalent
weight of at least 500 g/eq,

the quantities of constituents a), b), and c) adding up to 100 wt %.

[0126] It has furthermore proven to be advantageous, in an embodiment of
the present invention, if the second component of the two-component
composition according to the present invention contains, in addition to
the thiol group-containing hardener, an amine group-containing hardener
for epoxy resins.

[0127] These amine group-containing hardeners for epoxy resins can be
selected, for example, from the following compounds: cyclic tertiary
amines, aromatic amines, and/or mixtures thereof. The hardeners can be
incorporated stoichiometrically into the hardening reaction, but they can
also be catalytically active.

[0128] Adducts of amino compounds with epoxy resins are furthermore
suitable as accelerating additives. Suitable amino compounds are tertiary
aliphatic, aromatic, or cyclic amines. Suitable epoxy compounds are, for
example, polyepoxides based on glycidyl ethers of bisphenol A or F, or of
resorcinol. Concrete examples of such adducts are adducts of tertiary
amines such as 2-dimethylaminoethanol, N-substituted piperazines,
N-substituted homopiperazines, N-substituted aminophenols with di- or
polyglycidyl ethers of bisphenol A or F or of resorcinol.

[0130] The amino group-containing hardener or hardeners for epoxy resins
are contained in the agents according to the present invention by
preference in quantities from 0 to 20 wt %, based on the second component
made up of hardeners and optionally further formulation constituents.

[0131] In a preferred embodiment, the tertiary amines in particular have
proven to be particularly advantageous. They are contained in the agents
according to the present invention by preference in a quantity from 0 to
20 wt %, in particular from 5 to 15 wt %, based in each case on the
second component made up of hardeners and optionally further formulation
constituents.

[0132] Compositions whose second component contains or represents a
hardener for epoxy resins that is effective in a temperature range from 0
to 60° C., in particular from 0 to 25° C., are particularly
preferred according to the present invention.

[0133] In order to improve fracture behavior, in particular at
temperatures below 0° C., the preparations according to the
present invention can contain one or more different so-called toughness
improvers or "tougheners." Such tougheners are known to those skilled in
the art of epoxy adhesives. They can be selected, for example, from:
thermoplastic isocyanates or polyurethanes, rubber particles, in
particular those having a core-shell structure, and block copolymers, in
particular those that contain a first polymer block having a glass
transition temperature of less than 15° C. and a second polymer
block having a glass transition temperature of more than 25° C.
Such block copolymers are by preference selected from those in which a
first polymer block is selected from a polybutadiene or polyisoprene
block, and a second polymer block is selected from a polystyrene or
polymethyl methacrylate block. Specific examples thereof are block
copolymers having the following block structure:
styrene-butadiene-(meth)acrylate, styrene-butadiene-(meth)acrylic acid
esters, ethylene-(meth)acrylic acid ester-glycidyl(meth)acrylic acid
ester, ethylene-(meth)acrylic acid ester-maleic acid anhydride, methyl
methacrylate-butyl acrylate-methyl methacrylate.

[0134] It has furthermore proven advantageous according to the present
invention if the first component of the compositions according to the
present invention contains, in addition to the mixture of epoxy resins,
at least one inorganic and/or organic filler.

[0135] In a further embodiment, it has proven advantageous if the second
component of the composition according to the present invention contains,
in addition to the hardeners that are essential to the invention, at
least one inorganic and/or inorganic filler.

[0136] Fillers preferred according to the present invention are, for
example, the various ground or precipitated chalks, carbon black,
calcium-magnesium carbonates, talc, barite, and in particular silicate
fillers of the aluminum-magnesium-calcium silicate type, for example
wollastonite, chlorite.

[0137] For weight reduction, the preparation can also contain, in addition
to the aforesaid "normal" fillers, so-called lightweight fillers. These
can be selected from the group of the hollow metal spheres such as, for
example, hollow steel spheres, hollow glass spheres, fly ash (fillite),
hollow plastic spheres based on phenol resins, epoxy resins, or
polyesters, expanded hollow microspheres having a wall material made of
(meth)acrylic acid ester copolymers, polystyrene, styrene/(meth)acrylate
copolymers, and in particular of polyvinylidene chloride as well as
copolymers of vinylidene chloride with acrylonitrile and/or (meth)acrylic
acid esters, ceramic hollow spheres, or organic lightweight fillers of
natural origin such as ground nut shells, for example the shells of
cashew nuts, coconuts, or peanuts, as well as cork flour or coke powder.
Particularly preferred in this context are those lightweight fillers,
based on hollow microspheres, that ensure high compressive strength in
the cured preparation.

[0139] The two-component adhesives according to the present invention can
be used as adhesives, or as a matrix for a composite, a further
embodiment of the present invention being constituted thereby. The
adhesive can be utilized in particular for joining and repairing parts in
shipbuilding, aircraft construction, and vehicle construction. It is
notable for good processability and high strength on the one hand, and
particularly low health risk on the other. Further areas of application
for the systems according to the present invention are the do-it-yourself
sector, as well as the maintenance, repair, and overhaul sector for
vehicles, machines, and aviation, but areas of application in other
sectors of general industry are also encompassed according to the present
invention.

[0140] The agents according to the present invention are made up of two
components. These must be stored separately from one another until
immediately before utilization.

[0141] This can preferably be done by packaging in separate containers.
Removal of the preparation can then be accomplished immediately before
utilization. This can be accomplished by manually measuring out the
requisite quantities from storage vessels, for example drums.

[0142] In addition to purely manual measuring, dispensing can also be
accomplished using simple manual dispensing units or even fully automated
systems. Such systems are marketed, for example, by the Loctite company.
Examples of such automated systems are volumetric double gear pumps,
double precision piston dispensers, double screw pump dispensers, or drum
pump systems.

[0143] In a particularly preferred embodiment of the present invention,
the preparations according to the present invention are offered in
corresponding cartridges having a volume ratio of 1:1, 1:2, or 1:10
(component having epoxy resin mixture:component having thiol
group-containing hardeners). The selection of such double cartridges is
intended, according to the present invention, to ensure consistent
dispensing and thus a constant mixing ratio between the two components.
The cartridges according to the present invention can be emptied, upon
utilization, with the aid of simple manual dispensing units, but also
using pneumatic and/or completely automated systems.

[0144] A second subject of the present invention is therefore a dispensing
system that comprises two separate containers which, separately from one
another, contain the first and the second component of the compositions
according to the present invention, as well as a dispensing apparatus.

[0145] In another packaging form, the two components of the composition
according to the present invention can be coextruded and accordingly
packaged so as to be present directly next to one another until
utilization. The two components must then be thoroughly mixed with one
another at the time of utilization. This can be accomplished, for
example, by kneading the coextrudates.

[0146] A third subject of the present invention is therefore a composition
according to one of claims 1 to 9 that is presented as a coextrudate.

[0147] A fourth subject of the present invention is a method for joining
and/or repairing parts, in which method, in a first step, the two
components of the compositions according to the present invention are
mixed with one another, the resulting utilization mixture is applied onto
the overlapping surfaces of the parts to be joined, the parts are then
brought into contact with one another, and the utilization mixture then
cures.

[0148] The curing time depends, in this context, on the exact composition
of the system, the quantity applied, and the layer thickness, and can be
between a few minutes and several days.

EXEMPLIFYING EMBODIMENTS

1 Resin Mixtures

1.1 Producing the Resin Mixtures

[0149] The following resin mixtures were produced by mixing the individual
components and stirring vigorously at 70 to 100° C. for 1 hour.

1.2 Measuring Viscosities

[0150] Viscosities were measured on an ARES unit of the TA Instruments
company, New Castle, Del. 19720, USA, at a temperature of 25° C.,
and evaluated using TA Orchestrator software. At a viscosity <0.25
Pa*s, measurement was performed using a cone and plate (0.04°/25
mm) at a shear rate of 0 to 100/s. Viscosities >0.25 Pa*s and
<10,000 Pa*s were measured using parallel plates (25 mm/25 mm) at a
shear rate of 0 to 100/s. Viscosities >10,000 Pa*s were measured using
parallel plates (25 mm/25 mm) and at an angular frequency of 100 rad/s.

[0151] To determine the tensile shear strengths, components I and II as
indicated in Table 2 were thoroughly mixed with one another. Immediately
thereafter, two sandblasted, cold-rolled steel specimens with an overlap
area of 2.5 cm2 were wetted with the resulting adhesive at a layer
thickness of 0.2 mm, and bonded. The specimens were then cured for 7 days
at room temperature.

[0152] After that time, the tensile shear strength of the adhesive was
tested in accordance with DIN EN 1465 at a speed of 15 mm/min.

[0153] In determining the quantities of raw materials caused to react with
one another, care was taken to maintain a constant ratio between reactive
epoxy components and reactive thiol groups in the utilization mixture.
The respective equivalents used, and their ratios, are likewise evident
from Table 2.

[0154] The measured tensile shear strengths (LLS) clearly show that the
two-component compositions according to the present invention having
resins H1 to H3 are clearly superior to the two-component compositions
not according to the present invention having resins N1 to N3. It was
additionally possible to show by way of these measurements that the
tensile shear strengths of the systems according to the present invention
in fact turn out to be higher than the tensile shear strength of a
conventional adhesive based on DER 331, which has a high sensitizing
potential and is subject to labeling requirements.

[0155] In a further embodiment of the Examples, the fillers Luzenac 2,
Cabosil TS-720, and Omyacarb 4HD associated with component I in the
context of the Examples were also incorporated into components II.